Door skin, a method of etching a plate for forming a wood grain pattern in the door skin, and an etched plate formed therefrom

ABSTRACT

The present invention is directed to a door skin having an exterior surface with a wood grain pattern formed therein, and an etched plate for use as an embossing plate or with a molded die set, for forming the woodgrain pattern in the door skin.

CROSS-REFERENCE TO RELATED APPLICATIONS AND CLAIM TO PRIORITY

This application is a continuation of U.S. patent application Ser. No.12/912,156, filed Oct. 26, 2010, now U.S. Pat. No. 8,697,226, which is acontinuation of U.S. patent application Ser. No. 12/028,898, filed Feb.11, 2008, now U.S. Pat. No. 7,820,268, which is a continuation of U.S.patent application Ser. No. 11/327,401, filed Jan. 9, 2006, now U.S.Pat. No. 7,338,612, which is a division of U.S. patent application Ser.No. 10/346,187, filed Jan. 17, 2003, now U.S. Pat. No. 6,988,342, thecomplete disclosures of each of which are incorporated herein byreference.

FIELD OF THE INVENTION

The present invention is directed to an interior or exterior passagedoor door skin or other molded article, such as wainscot, furnituredoors, cabinet doors, decorative moldings, trim products, paneling,millwork, or the like, having a naturally appearing wood grain patternformed in an exterior surface. The invention is also directed to amethod of etching a plate, for use as an embossing plate or with amolded die set, for forming a wood grain pattern in the exterior surfaceof the door skin, and the resulting etched plate.

BACKGROUND OF THE INVENTION

Doors having compression molded door skins are well known in the art.Attempts have been made to provide a textured pattern on the exterior ofthe door skin to simulate the grain of natural wood. One such attemptprovides a printed wood grain pattern on the door skin. However, theprinted pattern has no depth or texture, as found in natural wood.Furthermore, the print ink often fails to provide for crisp wood grainlines, and varying tones.

Another attempt to simulate a natural wood grain pattern in the exteriorsurface of the door skin provides for transferring a photographic imageof the grain pattern onto an embossing plate, by an etching process, toform a lower surface and raised lines or ridges extending from the lowersurface of the metal plate. Etching is a process whereby areas of ametal plate are covered with an acid resistant ground and an acid ormordant solution is applied to the plate. The areas that have noresistant ground are eaten away by the acid. An image or pattern isetched into the metal plate that then has a lower surface, and raisedportions extending from the lower surface. The resistant ground, or“resist”, controls where and how the acid eats into the metal plate.Chromed steel, copper and zinc are three most common metals used foretching plates. Chromed steel is the hardest of the three metals, andwill not wear down as quickly as non-steel plates after repeatedembossing.

Different acids are necessary for etching different metals. In addition,there are different resists and ways of applying the resists. There arealso various ways to expose the metal to the acid after the resist hasbeen applied so that tone and texture can be created. Acid treatment ofthe plate then etches out the uncoated metal, creating a raised texturedsurface in the embossing plate. Raised ridges, or lines, are created byetching into the plate around lines of protective resist. The acid theneats away at the metal plate, leaving raised ridges that were protectedby the resist. The resulting structure creates an illusion of woodgrains. The depth of the etch into the metal is controlled by the widthof the corresponding line of resist that is removed.

Conventional etched plates may be used as an embossing plate, pressingthe etched image or pattern into a substrate. As known in the art, thesubstrate is subjected to selected amounts of heat, pressure and timeduring embossing. When embossing a material used to form a door skinhaving a wood grain pattern, the etched embossing plate is pressed intothe material to provide bundles of wood ticks that form the grainpattern on the resulting door skin surface. A wood grain pattern is acluster or bundle of spaced, raised lines, or “ticks”, which extend in apattern simulating the appearance of wood. The ticks must be carefullyspaced to simulate a natural wood grain. During etching, it is oftendifficult to achieve clear, crisp wood ticks. If the tick is too narrow,the acid may eat into the sides of the tick, and may completely destroythe tick. As such, conventional etched plates having wood grain patternsdo not emboss highly realistic wood ticks. In addition, suchconventional etched plates often have sharp edges on the outer surfacesof the ticks, and undercuts near the lower portions of the plate due tothe nature of the etching process. As the acid eats into the metalplate, grooves are cut therein. However, the acid also eats into thesides of ticks (separated by the groove), especially near the base ofthe groove. This is commonly known as undercutting, a phenomenon wellknown in the field of etching. The resulting ticks fail to simulate thesoft, flowing appearance of natural wood ticks.

In addition, conventional door skins with embossed wood grain patternsfail to capture the subtle wood tone variations found in natural wood.Natural wood includes not only wood ticks, but varying background tonesas well. Conventional embossing plates and molded die sets used to formdoor skins with wood grain patterns fail to capture both naturallyappearing wood ticks and wood tones. If the door skin surface isstained, it does not appear realistic. As commonly known in the art,stains include a dye or pigment in solution, and are generally used tocolor a wood by penetrating the wood surface. As such, the natural woodtones and ticks may be enhanced or colored, without covering the woodsurface textures and tones, as with paint. Stains do not penetrate thesurface of a synthetic door skin in the same manner as natural wood.Therefore, attempts to stain a door skin for purposes of enhancing tonesand ticks is a difficult process for a typical consumer. The stain maynot simply be applied with a brush or rag, and the excess wiped off, ascan be done with natural wood. Rather, multiple applications of stainare generally required, which must then be selectively removed by hand.This technique often requires a professional or one experienced instaining in order to capture a realistic wood appearance. Alternatively,portions of the door skin surface may be highlighted by spray gunapplication of the stain, or other shading material. Even if the stainis carefully applied in specific areas, the resulting tones and woodticks may appear splotchy and unrealistic. Thus, it is difficult toachieve the desired tonal variations.

Therefore, there is a need for a molded door skin having a wood grainpattern that may be easily stained, and that precisely captures both thewood ticks and wood tones found in natural wood grain.

SUMMARY OF THE INVENTION

The disclosed invention is directed to a molded door skin comprises anexterior surface having outer portions lying on a first plane, spacedgrooves recessed from the plane of the outer portions, and halftoneportions having spaced protrusions defined by channels. The channels arerecessed from the plane of the outer portions.

The disclosed invention also relates to other molded constructioncomponents, comprising an exterior surface having outer portions lyingon a first plane, spaced grooves recessed from the plane of the outerportions, and halftone portions having spaced protrusions defined bychannels. The channels are recessed from the plane of the outerportions.

A method of etching a wood grain pattern into a plate comprises thesteps of: capturing an image of a piece of wood having ticks andbackground tones; creating from the image a line art image substantiallyof modified ticks; creating from the image a background art imageincorporating modified background tones; rendering a master image fromthe line art image and the background art image; creating a patterntransfer from the master image; applying the pattern transfer to a metalplate; and etching the metal plate according to the pattern transfer.

An embossing plate for forming a wood grain pattern into a compositionmaterial comprises an etched metallic plate a lower portion lying on afirst plane, spaced ridges extending from the first plane, halftoneportions having a planar portion lying on a second plane and outwardlydisposed from the first plane, and spaced depressions extending from thesecond plane to the first plane.

A door comprises a peripheral frame, and at least one door skin. Thedoor skin has an exterior surface with outer portions lying on a firstplane, spaced grooves recessed from the plane of the outer portions, andhalftone portions. The halftone portions have spaced protrusions definedby channels, wherein the channels are recessed from the plane of theouter portions.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a front elevational view of a door skin having a wood grainpattern according to the present invention;

FIG. 2 is an enlarged perspective view of the circled portion 2-2 ofFIG. 1;

FIG. 3 is an enlarged cross-sectional view of the circled portion 2-2 ofFIG. 1;

FIG. 4 is an enlarged perspective view of the circled portion 4-4 ofFIG. 1;

FIG. 5 is a fragmentary perspective view of an etched metal plate havinglines and tonal areas;

FIG. 6 is a is a fragmentary line art image magnified by 300%; and

FIG. 7 is a fragmentary screen art image magnified by 300%.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is directed to a door skin D having a naturallyappearing wood grain pattern formed in an exterior surface 10, as bestshown in FIG. 1. The wood grain pattern may be formed using an etchedplate, such as in an embossing plate or molded die set, or other processknown in the art. As best shown in FIGS. 2 and 3, exterior surface 10 ofdoor skin D comprises a plurality of spaced grooves 12. Each one ofgrooves 12 is defined by opposing walls 14 and a base 16. A plurality ofouter portions 18 lie on a first plane that includes the most exteriorlydisposed surfaces of exterior surface 10. Interfaces 15 interconnect andare integral with outer portions 18 and walls 14. Preferably, interfaces15 are curved. Outer portions 18 separate adjacent grooves 12.Preferably, grooves 12 are recessed from the first plane from betweenabout 0.003 inches to about 0.013 inches, and may have variable widths.As such, outer portions 18 may also have variable widths, as best shownin FIG. 2. The depth of grooves 12 may vary beyond the preferred rangedepending on the substrate used to mold door skin D (or other moldedarticle), as well as the wood species being simulated.

In addition, adjacent grooves 12 may be spaced from each other byvariable distances, and extend longitudinally relative to each other byvariable lengths, as best shown in FIG. 1. Grooves 12A, 12B and 12C arespaced from each other, extending in an arrowhead-like configuration, asmay be found in a natural wood. Grooves 12D, 12E and 12F extendlongitudinally, extending the entire length of door D. It should beunderstood that the configuration of grooves 12 simulates natural wood.As such, while some grooves 12 may extend substantially parallel andspaced a predetermined distance, they need not, as shown in FIG. 1.Thus, the configuration of grooves 12 simulates an appearance of soft,flowing wood ticks.

In addition, exterior surface 10 includes halftone portions 20. Each oneof halftone portions 20 includes a plurality of recessed channels 22.Channels 22 are preferably recessed from the first plane of outerportions 18 to a depth of between about 0.001 to about 0.003 inches,more preferably 0.003 inches. The preferred depths simulate a woodspecies such as ash. However, the depths may vary beyond the preferredranges, depending on the substrate being embossed and/or molded and thewood species being simulated. Channels 22 are configured in a grid-likepattern, and are preferably recessed from the first plane about the samedepth throughout exterior surface 10. Channels 22 define a plurality ofspaced protrusions 24. Spaced protrusions 24 are preferably box-shapedin configuration (as defined by the grid-like pattern of channels 22),as best shown in FIG. 2. However, spaced protrusions 24 need not bebox-shaped. For example, halftone portions 20 may include a plurality ofcylindrically shaped protrusions 24. Each one of spaced protrusions 24includes a flat top 25, which is coplanar with the first plane of outerportions 18, or slightly recessed from the first plane. Spacedprotrusions 24 also include sides 27 extending from channels 22 to flattops 25. Because channels 22 are recessed from the first plane frombetween about 0.001 inches to about 0.003 inches, protrusions 24correspondingly extend upward from channel portions 22 from betweenabout 0.001 inches to about 0.003 inches. However, protrusions 22 do notextend beyond the first plane of outer portions 18 (though they may becoplanar with the first plane).

Halftone portions 20 include varying numbers of spaced protrusions 24,depending on the spacing of channels 22. Preferably, halftone portions20 have 133 or fewer protrusions 24 per inch. However, it should beunderstood that the maximum number of protrusions per inch may varydepending on the substrate used to form door skin D, or the species ofwood being simulated. A halftone portion 20 having a relatively highnumber of protrusions 24 is best shown in FIG. 2. A halftone portion 20having a relatively low number of protrusions 24 is best shown in FIG.4. While halftone portions 20 are shown as disposed between grooves 12,some portion of the area between adjacent grooves 12 have no halftoneportions, and thus provide a bi-color or glossy appearance after stainis applied to exterior surface 10.

As best shown in FIGS. 2 and 4, halftone portions 20 may includevariably sized protrusions 24. A halftone portion 20 having a relativelyhigh density of protrusions 24 includes smaller protrusions 24, as bestshown in FIG. 2. A halftone portion 20 having a relatively low densityof protrusions 24 includes larger protrusions, as best shown in FIG. 4.Channels 22 defining adjacent protrusions 24 have a substantiallyconsistent width throughout exterior surface 10. However, adjacentchannels 22 may be variably spaced, depending on the size of protrusions24. Therefore, a halftone portion 20 having a high density ofprotrusions 24 includes more closely spaced channels 22, as compared toa halftone portion 20 having a low density of protrusions 24.

Therefore, exterior surface 10 of door skin D includes a plurality ofgrooves 12 and halftone portions 20 that simulate wood ticks andbackground wood tones, respectively, as found in natural wood grain.When stain is applied to exterior surface 10, varying amounts of stainaccumulate in grooves 12, since grooves 12 are variably spaced and havevariable widths and depths. Deeper, wider grooves 12 hold more stain ascompared to shallower, narrower grooves 12. In this way, the deeper,wider grooves 12 simulate darker, more prominent wood ticks. Similarly,shallower grooves 12 simulate lighter, more delicate wood ticks.Likewise, halftone portions 20 having many, closely spaced channels 22retain more stain as compared to halftone portions 20 having fewerchannels 22 that are not as closely spaced. The more stain that isretained in a given halftone portion 20, the darker the area willappear. Thus, varying halftone portions 20 simulate varying wood tones,depending on the configuration of channels 22 and protrusions 24.

Stain may easily be applied to exterior surface 10 of door D by an enduser simply by wiping the stain on exterior surface 10. The integrationand configuration of grooves 12 and halftone portions 20 allow the stainto be simply wiped or brushed on by the consumer. Excess stain is thenwiped off. Thus, stain is applied to the disclosed molded door skin D inthe same manner as it is applied to natural wood. Furthermore, only onecoat of stain may be required, depending on the preference of the enduser. Preferably, a heavily pigmented stain is used, which will easilycling and congeal in grooves 12 and halftone portions 20.

The present invention is also directed to an etched plate P, for use asan embossing plate or with a molded die set for forming a wood grainpattern in the exterior surface of a molded article, such as door skinD. As best shown in FIG. 5, a metal plate P includes a plurality ofetched lines 30 extending upwardly from lower portions 32, wherein lowerportions 32 lie on a plane that include the deepest etched surfaces of ametal plate P. Lines 30 have a ridge-like configuration, and vary inheight from between about 0.003 inches to about 0.013 inches. The heightof lines 30 may vary depending on the particular wood species that isbeing simulated. Each one of lines 30 includes an upper ridge 34, andwalls 36 extending from upper ridge 34 to lower portions 32. Adjacentlines 30 are separated by gaps 38, which are etched into plate P todefine lines 30. Plate P has an inverse configuration to the exteriorsurface being formed on door D. For example, lines 30 correspond togrooves 12 of door D, and the plane of lower portions 32 correspond tothe first plane of outer portions 18 and flat tops 25.

Plate P also includes tonal portions 40, which correspond to halftoneportions 20 when embossing an article. For example, tonal portions 40correspond to halftone portions 20 of door D. Tonal portions 40 includea planar area 42 with a plurality of depressions 44 spaced throughoutplanar area 42. Because tonal portions 40 have an inverse configurationto the halftone portion in an embossed article, such as halftoneportions 20, tonal portions 40 are configured as a raised grid, as bestshown in FIG. 5. As such, depressions 44 are configured as a box-like,open areas recessed from planar area 42. Depressions 44 include sides 46and a base 48. Base 48 is coplanar with lower portions 32, oralternatively slightly raised from lower portions 32. Planar areas 42are etched into plate P to a depth of between about 0.010 inches toabout 0.014 inches, preferably 0.010 inches. Depressions 44 are etchedan additional about 0.001 inches to about 0.003 inches from planar areas42. The depth of the etch may vary depending on the particular woodspecies that is being simulated. As such, the grid-like configuration ofplanar areas 42 in tonal portions 40 has a height of about 0.001 toabout 0.003 inches relative to lower portion 32.

Similar to protrusions 24, the density and size of depressions isvariable in a given planar area 42. Thus, the configuration of tonalportions 40 that are etched into plate P precisely controls the tonalvariations in an embossed article, such as door D. Similarly, theconfiguration of lines 30 that are etched into plate P control thequalities of the simulated ticks (i.e. grooves 12) in a molded orembossed article. The disclosed etched plate P may be used as anembossing plate or with a molded die set for embossing and molding awood grain pattern into an article. The resulting surface formed byplate P creates a stainable surface, wherein the stain may be simplywiped on by the consumer.

A method of etching a plate, for use as an embossing plate or with amolded die set, integrates etching lines in a metal plate at varyingheights with etching tonal portions in the plate using a screeningprocess. Prior to etching, images of natural pieces of wood arephotographed to derive the actual texture, tones and tick pattern to besimulated. Preferably, each natural wood board is prepared forphotography by burning and wire brushing the board surface, whichaccentuates the fine ticks, background color and tone of the board. Theimage of the prepared board may then be captured using conventionalphotography methods. Alternatively, the image may be derived usingdigital imaging techniques, as known in the art. A plurality of boardsmay be photographed, each representing a stile, rail, and panel of theultimately to be produced door skin. The boards may be of different woodspecies, so that the stiles and rails may be one species and the panelsanother species. The photographs may then be assembled into theappearance of a door, with the wood grain pattern of each board orientedas desired. Thus a naturally appearing door may be achieved, with thewood grain of the stiles oriented perpendicular to that of the rails,and the wood grain of the panel(s) oriented as desired.

The image is then altered using either conventional photographic arts orusing computer imaging. Specifically, the image is processed by colorseparation, whereby the initial image is separated by camera or computerimaging to produce a first image showing all of the wood ticks from theinitial image, and a second image showing all of the wood tones from theinitial image.

The first image is enhanced by increasing resolution, thereby creatingan image of “flowing” ticks using filters such as available in computersoftware such as Photoshop™. Specifically, the size of the image isincreased, preferably by about 300%. Resolution of the image is thenincreased, preferably from about 600 dpi to about 2400 dpi. In this way,the thickness of the ticks may be easily adjusted and spaced in theimage to avoid etching lines that are too close to each other.Preferably, this adjustment involves scaling all ticks shown in theimage based upon the thickest tick as the baseline or reference againstwhich all other ticks are dimensioned. As described above, lines 30 areformed in a metal plate by etching around lines 30 and thereby forminggaps 38. As the acid eats into the metal, forming gaps 38, the acid hasa tendency to bite into walls 36 of lines 30 and thereby widening gaps38. If lines 30 are too narrow or “clumped” (i.e. adjacent gaps 38 aretoo close), the acid may etch completely through walls 36 of a line 30,thereby destroying such a narrow line 30. This is commonly known as“choking and spreading”. In order to eliminate this problem, the imageof the ticks is modified by adjusting the thickness and spacing of theticks in the initial image (which will be lines 30 in the plate). Amodified first image is created, referred to hereafter as the “line artimage”. The resulting enhanced line art image avoids clumping, whilemaintaining a precise simulation of the wood grain ticks from theinitial image. A line art image magnified by 300% is shown in FIG. 6,showing several bundles of ticks 100.

The second image is enhanced by photographic or computer modelingtechniques to control density of the wood tones. Preferably, thebackground of the initial image is combined with a 133 screen at 40%resolution. As known in the art, a 133 screen has 133 lines per inch. Aresolution of 40% controls the density of the tones. Although screensare known in the printing industry, such conventional screening usuallyapplies to geometric patterns and natural art such as leathers. Thescreen allows for modification and adjustment of the tones, therebyallowing the denser tones to etch. The resulting modified image isconverted to film, thereby creating an enhanced second image, referredto hereafter as the “screen art image”. A screen art image magnified by300% is shown in FIG. 7, showing tonal variations 200A, 200B and 200C.The half tones are adjusted also so as to be sufficiently large toprevent them from being occluded by the molding material during theembossing or molding process.

Once useable film is rendered from the line art image and screen artimage, it is developed into a photo sensitized lithography plate to beused as a pattern master. Preferably, the photography is applied to apre-sensitized magnesium plate. A wax base material is applied to themaster plate to create a pattern transfer. Different wax formulationsare used for etching that correspond to the line art image (“line artwax”), and for etching that correspond to the screen art image (“screenart wax”). Preferably, bee's wax-based wax resist formulations are used,such as available from Custom Etch, Inc. of New Castle, Pa. The line artwax holds onto the plate longer during the etch process, as compared tothe screen art wax. The screen art wax provides more detail, and dropsoff sooner in the etch process as compared to the line art wax.

The master plate is waxed, and a paper impression is then taken from themaster plate. The wax clings to the paper where the pattern has beenetched into the plate during the development process. The resulting waxtransfer is lifted from the master plate using a flexible tissuecarrier, and transferred to a metal plate to be etched after the platehas been thoroughly cleaned, leaving the wax resist art on the plate. Ifmultiple pattern transfers are used, the transfers must be aligned andjoined together. The transfer is burnished onto the surface and, withthe use of a releasing agent, the tissue carrier is removed. Any matchlines and fitted contours are blended using a liquid acid-resistantmaterial to create a uniform pattern transition and blend. Preferably,the wax is left on the plate for about 24 hours before etching.

Preferably, the plate to be etched is a premium grade of steel with lowcarbon content. For example, SP300 steel, known in the art as “cleansteel” may be used. Such premium grade steel is generally morehomogenous than standard grade steel, and has a micrograin with tightcellular structure. Standard grade steel does not provide a tightcellular structure for the delicate line and screen etching required inthe present invention, resulting in a rough background lackingdefinition.

After the wax resist art has been transferred to the plate, all areasoutside of the plate which are not be etched are masked out using anacid resistant tape. This procedure is repeated in greater detail withclose tolerance masking areas inside the plate that are not to beetched, thereby protecting untextured shutoffs, borders and nominaldraft areas. Upon completion of this stage, all masking seams are sealedoff with another wax base material to insure that no acid will leak intothe protected area. The unmasked areas are then vapor honed. Vaporhoning involves directing abrasive particles carried in water or air.Preferably, a mix of aluminum oxide and glass beading is used tosatinize the desired texture area to aid in the adherence of the patterntransfer. After inspection, the mold is ready for etching.

Etching methods and acid formulas to be utilized are determined based onthe type of metal, the desired depth of pattern, and the size of plateor die to be etched. The type of metal will determine the proper acidformula to be used. Preferably, a nitric based acid is used, such asavailable from Custom Etch, Inc. of New Castle, Pa. Etching depth isgoverned by the temperature of the mold and acid, the amount of time themold is exposed to the acid, and the width of the lines of resist thatare removed. The width and depth of the gaps being etched (and thereforethe width and height of the lines being formed) is determined andadjusted based on the initial image. The wider the line of resist thatis removed, the deeper the etch, and vice versa. The major lines aredefined by gaps that are etched to a depth of between about 0.009 to0.013 inches. More delicate lines are defined by gaps that are etched toa depth of between about 0.003 to about 0.008 inches. Correspondingly,the resulting lines range in height from between about 0.009 inches toabout 0.013 inches. The taller lines 30 create a deeper groove 12,forming a darker, more prominent groove 12 on the exterior surface 10after stain is applied. The depths may vary outside the preferred rangedepending on the species of wood being simulated.

The line art is etched in the acid bath for approximately 40-50 minutes.Following the line art etching, the plate is again cleaned to remove anyacid and/or particulates. In addition, the plate is vapor honed andthoroughly washed with another acid formulation, or “post-wash”, toremove any undercuts. The vapor honing and post wash also remove anysharp edges that may have formed during etching, thereby achieving soft,flowing lines by slightly rounding and polishing any sharp edges as wellas removing any undercuts.

After the thorough cleaning and removal of undercuts, the etched lineart is covered with the screen art wax. The plate is re-etched using afast-acting acid for approximately 8-10 minutes. The tonal portions areetched to a depth of between about 0.012 to 0.013 inches, wherein theplanar area 42 is etched to a depth of about 0.010 inches to about 0.013inches, and the depression an additional depth of about 0.001 to about0.003 inches from planar area 42. The plate is again cleaned and vaporhoned to brighten the surfaces, and remove any resulting sharp edges andundercuts. However, the screen art is not post-washed with acid, givendepressions 44 could be removed by post-washing. A layer of hard chromeis then applied to the finished etched plate, and resists wear afterrepeated embossing.

The resulting etched plate has a multi-level effect of line artintegrated with screen art, as best shown in FIG. 5. This integrationachieves flowing ticks and subtle tonal variations in a molded articleembossed or formed with the disclosed etched plate, precisely simulatingthe qualities and appearance of natural wood. In addition, undercuts andsharp edges are eliminated, further enhancing the detail and crispappearance of the line art.

Various substrates may be used to form an article having a wood grainpattern formed from the disclosed etched plate. Preferably, a polymericsubstrate is used, such as sheet molding compound (SMC), polystyrene orpolypropylene. However, it should be understood that various othersubstrates may be used in the present invention, such as medium densityfiberboard (MDF), hard board, fiberboard, other wood compositematerials, and other thermoplastic materials. The coloration of theresulting article is preferably a wood toned color. However, any basecoloration may be used. Furthermore, stain or other dye may be appliedto the article. Preferably, a stain having a heavy loading of pigment isused, in order to easily cling in the etched grooves and halftoneportions.

Although the present invention has been described herein with respect toa molded door skin, it should be understood that the present inventionis applicable to the formation of many other molded articles having woodgrain patterns, such as wainscot, furniture doors, cabinet doors,paneling, decorative moldings, trim board, millwork, constructioncomponents, and the like.

It will be apparent to one of ordinary skill in the art that variousmodifications and variations can be made in construction orconfiguration of the present invention without departing from the scopeor spirit of the invention. Thus, it is intended that the presentinvention cover all modifications and variations of the invention,provided they come within the scope of the following claims and theirequivalents.

What is claimed is:
 1. A molded door skin, comprising a molded componenthaving a stainable exterior surface comprising molded grooves and moldedhalftone portions, the grooves configured with variable depths andlengths with respect to one another and variably spaced with respect toone another to collectively simulate an appearance of a naturallyappearing wood grain tick pattern, the halftone portions configured toreceive and retain sufficient stain to simulate an appearance ofdarkened naturally appearing wood grain background tone.
 2. The moldeddoor skin of claim 1, wherein a first area of the exterior surface has afirst density of the halftone portions, wherein a second area of theexterior surface has a second density of the halftone portions, andwherein the first density differs from the second density so that whenstain is received and retained in the halftone portions the first andsecond areas simulate naturally appearing wood background tones havingdifferent degrees of darkness.
 3. The molded door skin of claim 1,wherein a first area of the exterior surface has a plurality of thehalftone portions disposed between a first plurality of the grooves toprovide a first tone when stain is received and retained in the halftoneportions, wherein a second area of the exterior surface has none of thehalftone portions between a second plurality of the grooves to provide asecond tone when the exterior surface is stained, and wherein the firstand second tones respectively of the first and second areas collectivelyprovide a bi-tonal appearance.
 4. The molded door skin of claim 1,wherein the molded component comprises at least one polymeric materialselected from sheet molding compound, polystyrene, polypropylene, orcombinations thereof.
 5. The molded door skin of claim 1, wherein themolded door skin is sized as an interior or exterior passage door skin.6. The molded door skin of claim 1, wherein the stainable exteriorsurface has stile regions and rail regions simulating stiles and railsof the molded door skin, the grooves in the stile regions extendingsubstantially perpendicularly to the grooves in the rail regions.
 7. Themolded door skin of claim 1, wherein the halftone portions compriserecesses configured to receive and retain sufficient stain to simulatethe appearance of the darkened naturally appearing wood grain backgroundtone.
 8. The molded door skin of claim 1, wherein: the grooves areseparated from one another by outer portions arranged on the exteriorsurface; and a plurality of the halftone portions are situated in theouter portions between the grooves.
 9. The molded door skin of claim 1,wherein: the grooves are separated from one another by outer portionsarranged on the exterior surface, the grooves having first depths; andthe halftone portions comprise recesses situated in the outer portionsbetween the grooves and configured to receive and retain sufficientstain to simulate the appearance of the darkened naturally appearingwood grain background tone, the recesses having second depths that areless than the first depths.
 10. A door selected from an interior passagedoor or an exterior passage door, the door comprising: a frame havingopposite first and second sides; and a first molded door skin sized asan interior or exterior passage door skin, the first molded door skinsecured to the first side of the frame and comprising a first moldedcomponent having a first stainable exterior surface comprising moldedfirst grooves and molded first halftone portions, the first groovesconfigured with variable depths and lengths with respect to one anotherand variably spaced with respect to one another to collectively simulatean appearance of a first naturally appearing wood grain tick pattern,the first halftone portions configured to receive and retain sufficientstain to simulate an appearance of a first darkened naturally appearingwood grain background tone.
 11. The door of claim 10, further comprisinga second molded door skin secured to the second side of the frame andcomprising a second molded component having a second stainable exteriorsurface comprising molded second grooves and molded second halftoneportions, the second grooves configured with variable depths and lengthswith respect to one another and variably spaced with respect to oneanother to collectively simulate an appearance of a second naturallyappearing wood grain tick pattern, the second halftone portionsconfigured to receive and retain stain to simulate an appearance of asecond darkened naturally appearing wood grain background tone.
 12. Thedoor of claim 10, wherein a first area of the first stainable exteriorsurface has a first density of the first halftone portions, wherein asecond area of the first exterior surface has a second density of thefirst halftone portions, and wherein the first density differs from thesecond density so that when stain is received and retained in the firsthalftone portions the first and second areas simulate naturallyappearing wood background tones of different degrees of darkness. 13.The door of claim 10, wherein a first area of the first exterior surfacehas a plurality of the first halftone portions disposed between a firstplurality of the first grooves to provide a first tone when stain isreceived and retained in the first halftone portions, wherein a secondarea of the first exterior surface has none of the first halftoneportions between a second plurality of the first grooves to provide asecond tone when the first exterior surface is stained, and wherein thefirst and second tones respectively of the first and second areascollectively provide a bi-tonal appearance.
 14. The door of claim 10,wherein the first molded component comprises at least one polymericmaterial selected from sheet molding compound, polystyrene,polypropylene, or combinations thereof.
 15. The door of claim 10,wherein the first stainable exterior surface has stile regions and railregions simulating stiles and rails of the first molded door skin, thefirst grooves in the stile regions extending substantiallyperpendicularly to the first grooves in the rail regions.
 16. The doorof claim 10, wherein the first halftone portions comprise recessesconfigured to receive and retain sufficient stain to simulate theappearance of the first darkened naturally appearing wood grainbackground tone.
 17. The door of claim 10, wherein: the first groovesare separated from one another by outer portions arranged on the firststainable exterior surface; and a plurality of the first halftoneportions are situated in the outer portions between the first grooves.18. The door of claim 10, wherein: the first grooves are separated fromone another by outer portions arranged on the first stainable exteriorsurface, the first grooves having first depths; and the first halftoneportions comprise recesses situated in the outer portions between thefirst grooves and configured to receive and retain sufficient stain tosimulate the appearance of the first darkened naturally appearing woodgrain background tone, the recesses having second depths that are lessthan the first depths.
 19. A stained molded door skin, comprising amolded component having a stained exterior surface comprising moldedgrooves and molded halftone portions stained with a stain, the groovesconfigured with variable depths and lengths with respect to one anotherand variably spaced with respect to one another to collectively simulatean appearance of a naturally appearing wood grain tick pattern, thehalftone portions retaining a sufficient amount of the stain to simulatean appearance of darkened naturally appearing wood grain backgroundtone.
 20. The stained molded door skin of claim 19, wherein a first areaof the exterior surface has a first density of the halftone portionsretaining a first amount of the stain to provide a first tone, wherein asecond area of the exterior surface has a second density of the halftoneportions retaining a second amount of the stain to provide a secondtone, and wherein the first tone differs from the second tone tosimulate multiple naturally appearing wood background tones of differentdegrees of darkness.
 21. The stained molded door skin of claim 19,wherein a first area of the exterior surface has a plurality of thehalftone portions disposed between a first plurality of the grooves toretain a first amount of the stain to provide a first tone, wherein asecond area of the exterior surface has none of the halftone portionsbetween a second plurality of the grooves to provide a second tone, andwherein the first and second tones respectively of the first and secondareas collectively provide a bi-tonal appearance.
 22. The stained moldeddoor skin of claim 19, wherein the molded component comprises at leastone polymeric material selected from sheet molding compound,polystyrene, polypropylene, or combinations thereof.
 23. The stainedmolded door skin of claim 19, wherein the molded door skin is sized asan interior or exterior passage door skin.
 24. The stained molded doorskin of claim 19, wherein the stained exterior surface has stile regionsand rail regions simulating stiles and rails of the stained molded doorskin, the grooves in the stile regions extending substantiallyperpendicularly to the grooves in the rail regions.
 25. A door selectedfrom an interior passage door or an exterior passage door, the doorcomprising: a frame having opposite first and second sides; and a firststained molded door skin sized as an interior or exterior passage doorskin, the first stained molded door skin secured to the first side ofthe frame and comprising a first molded component having a first stainedexterior surface comprising molded first grooves and molded firsthalftone portions stained with a stain, the first grooves configuredwith variable depths and lengths with respect to one another andvariably spaced with respect to one another to collectively simulate anappearance of a first naturally appearing wood grain tick pattern, thefirst halftone portions retaining a sufficient amount of the stain tosimulate an appearance of a first darkened naturally appearing woodgrain background tone.
 26. The door of claim 25, further comprising asecond molded door skin secured to the second side of the frame andcomprising a second molded component having a second stained exteriorsurface comprising molded second grooves and molded second halftoneportions stained with the stain, the second grooves configured withvariable depths and lengths with respect to one another and variablyspaced with respect to one another to collectively simulate anappearance of a second naturally appearing wood grain tick pattern, thesecond halftone portions configured to receive and retain additionalstain to simulate an appearance of a second darkened naturally appearingwood grain background tone.
 27. The door of claim 25, wherein a firstarea of the first exterior surface has a first density of the firsthalftone portions retaining a first amount of the stain to provide afirst tone, wherein a second area of the first exterior surface has asecond density of the first halftone portions retaining a second amountof the stain to provide a second tone, and wherein the first tonediffers from the second tone to simulate multiple naturally appearingwood background tones of different degrees of darkness.
 28. The door ofclaim 25, wherein a first area of the first exterior surface has aplurality of the first halftone portions disposed between a firstplurality of the first grooves to retain a first amount of the stain toprovide a first tone, wherein a second area of the first exteriorsurface has none of the halftone portions between a second plurality ofthe first grooves to provide a second tone, and wherein the first andsecond tones respectively of the first and second areas collectivelyprovide a bi-tonal appearance.
 29. The door of claim 25, wherein thefirst molded component comprises at least one polymeric materialselected from sheet molding compound, polystyrene, polypropylene, orcombinations thereof.
 30. The door of claim 25, wherein the firststained exterior surface has stile regions and rail regions simulatingstiles and rails of the first stained molded door skin, the firstgrooves in the stile regions extending substantially perpendicularly tothe first grooves in the rail regions.